Well, I noticed that my prototype example as described in my previous part 1 post was broken as I suspected would happen at some point. So, I decided I would spend a few minutes and modify it to use the Google API. The API wasn't available when I first started putting this together so I had to resort to hacking techniques. Its now operating nicely with the API.
Update: Brent passed this along today (http://ajax.phpmagazine.net/2006/02/network_monitoring_with_ajax.html) and reminded me of Herve Guy's network monitoring with JSRS since 2001 (see http://www.canarie.ca/canet4/monitoring/use.html).